>>20353392it's unnatural for two vowels to occur right next to each other. for example, something like "idea of it". people naturally insert consonants to avoid this.
in england, an r is sometimes added between "idea" and "of" for idearof it.
it depends on the vowels though. it can be a y-sound like in "fire"
in america, people tend to opt for a glottal stop (like in german)
